Public Service Commission of the District of Columbia — Pipeline Safety Interpretation

Page 1Ms Mary E. Brazelton Executive Secretary Public Service Commission of the District of Columbia 1625 I Street, N.W. Washington, D.C. 20006 Dear Ms. Brazelton: This responds to your letter of November 18, 1977, asking us to clarify an apparent difference of opinion on whether the Washington Gas Light Company (WGL) operates transmission lines in the District of Columbia. After reviewing the matter, it appears that the issue may involve a misunderstanding of the definition of the term "transmission line" as set forth in 49 CFR 192.3. This definition provides, in relevant part, that a pipeline is a "transmission line" if it "transports gas from a gathering line or storage facility to a distribution center of storage facility." Referring to this definition, the WGL concludes in its letter to you dated October 31, 1977, that it does not have any transmission lines in the District of Columbia in part because it "has no gathering lines or gas storage fields within the District." This conclusion does not follow, however, because neither ownership of, nor the presence of, gas storage fields or gathering lines in the District is determinative of whether lines operated by the WGL in the District are properly classified as transmission lines. In the October 7, 1977, colloquy, Mr. Heverly referred to WGL-operated pipelines running between interstate transmission lines outside the District and distribution centers inside the District as "transmission lines." In our view, his interpretation is correct. With the classification scheme of Part 192, the true beginnings of these lines are not the interstate lines, themselves, but the sources of the interstate lines. These WGL-owned lines are merely extensions of transmission lines which begin at junctures with gathering lines or storage fields located outside the District. We trust that this analysis will be useful to the Commission in carrying out its enforcement responsibilities. Sincerely, Cesar DeLeon Acting Director DB C:\WP51\INTERPRT\192\3\77-12-09 1#

Page 2Office of Pipeline Safety Operations DB C:\WP51\INTERPRT\192\3\77-12-09 2#